Upgrade ESXi Drivers

If you upgrade vSphere, hardware drivers are not always upgraded equally! During one use case I ran into iSCSI performance issues after upgrading to ESXi 5.5. After doing some research it appeared that ESXi 5.0 NIC drivers were still installed on the ESXi host, the 5.5 upgrade package didn’t contain newer NIC drivers. In most cases this will not be any problem but in my case it was, after installing the latest NIC drivers the iSCSI problems were gone.

Don’t be alarmed some upgrade packages do contain more recent version of drivers, VMware refers to these drivers as ‘inbox’, the latest driver version the ‘async’ driver can be downloaded from the VMware website. Please refer to the manual below how to: